Chain saw apparatus for producing semi-tubular shapes



Oct. 15, 1957 s. K. NETHERY, JR, EIAL CHAIN sAw APPARATUS FOR PRODUCING SEMI-TUBULAR SHAPES Filed Jan. 4, 1955 4 Sheets-Sheet 1 MALI/7M 0. M/77/,

ATTORNEY s. K. NETHERY, JR, ETAL 2,309,680

Oct. 15, 1957 CHAIN sAw APPARATUS FOR PRODUCING SEMI-TUBULAR SHAPES 4 SheetsSheet 2 Filed Jan. 4, 1955 aux,

ATTORNEY Oct. 15, 1957 s. K. NETHERY, JR, ETAL I 2,309,680

CHAIN SAW APPARATUS FOR PRODUCING SEMI-TUBULAR SHAPES 4 Sheets-Sheet 5 Filed Jan. 4, 1955 INVENTORS ATTORNEY Oct. 15, 1957 s. K. NETHERY, JR, ETAL v2,809,680

CHAIN SAW APPARATUS FOR PRODUCING SEMI-TUBULAR SHAPES Filed Jan. 4, 1955 4 Sheets-Sheet 4 I NVENTORS Unite all CHAW SAW APPARATUfi FUR PRODUCING SEWEUBULAR SHAPES Stanton K. Nethery, 3L, and William (B. Smith, Freeport,

Tern, assignors to The Dow Chemical Company, Midland, Mich, a corporation of Delaware Appiieation January 4, 1955, Serial No. 479,782

5 Claims. ((11. 14332) This invention relates to a method and apparatus for producing semi-tubular shapes. More particularly, the present invention relates to an improved method and apparatus for producing semi-tubular shapes from insulative material, said semi-tubular shapes having substantial axial curvatures.

For many years it has been common practice to position insulative covering material over tubes or other conduits which conduct fluids having temperatures substantially different from ambient temperature, the covering serving to insulate the tube or pipe and its contents from the surrounding atmosphere in order to prevent radiant heat loss or absorption.

In order to provide such insulative covering in a readily installable form, it has been almost universal practice to provide the insulative material in semi-tubular complementary sections. These semi-tubular complementary sections are fitted together over the previously installed piping and are held in place by means of clamps, bands, adhesives or the like.

It will be understood that the term semi-tubular as used in this specification and the appended claims is intended to define and include an axial section of tubing designed to provide a close covering fit over a portion of any of the standard forms of commercial tubing, regardless of the cross sectional configuration thereof. Such cross sectional configuration may take the shape of an oval, a circle, a polygon or the like. It will also be understood that the semi-tubular section need not be exactly one-half of the overall assembled structure, since in many instances it is desirable to produce complementary sections wherein one of the sections covers over 180 of the perimeter of the pipe and the mating section covers the remaining portion thereof.

In recent years the rapid expansion of chemical refining industries, particularly those relating to the hydrofining and catalytic cracking of petroleum and those relating to the production of synthetic plastic materials, has brought about an ever increasing need for a ready, inexpensive means to manufacture such insulative covering. A single modern petroleum refinery plant may include many miles of tubes or pipes carrrying highly heated fluids. Due to the particular configuration of the tanks and reactors utilized in such a plant and to the series flow problems involved therein, such tubes and pipes of necessity have incorporated therein a number of elbow and reverse bends, as Well as S-sections and similarly curved shapes.

While a number of processes and apparatus have been successfully utilized for the production of straight sections of insulative material to cover these pipes, it has heretofore been exceedingly diflicult and expensive to produce insulative covering having axial curvature to fit over the elbow or other bends of the pipes. Since a very substantial portion of the pipes in modern chemical refineries and chemical production plants is taken up by such axially curved piping, the cost of the overall insulation for this piping has in the past been very substantial, in some instances running to a cost approximately equal to that of the piping itself.

It is, therefore, an object of this invention to provide a simple and inexpensive method and apparatus for producing axially curved, semi-tubular sections of insulative material.

Another object of this invention is to provide a method and apparatus for readily producing on a single machine axially curved, semi-tubular sections of diflferent cross sections and of different degrees of curvature.

Another object of this invention is to provide an improved chain saw machine and feed therefor having extreme simplicity in its construction and method of operation, which machine will accurately reproduce the desired semi-tubular insulative shapes.

It is a further object of this invention to provide such a chain sawing machine having interchangeable, adjustable arbors and incorporating therewith a synchronously driven conveyor feed.

A still further object of the invention is to provide such a method and apparatus particularly suitable for the sawing of insulative semi-tubular shapes from blocks of light weight cellular material.

Further objects and advantages of the present invention will be apparent to those skilled in the art from the following detailed description and by the disclosure of the construction shown by way of illustration in the accompanying drawings, in which:

Fig. 1 is a view in perspective of the overall structure of one embodiment of the apparatus of the present invention;

Fig. 2 is a front sectional elevation taken on the line 22 of Fig. 3;

Fig. 3 is a side sectional elevation of the apparatus taken on the line 33 of Fig. 2;

Fig. 4 is a partial plan view of the apparatus;

Fig. 5 is a view in perspective of a partially completed semi-tubular section as it is manufactured from a block L of insulative material according to the present method and apparatus;

Fig. 6 is an enlarged detailed sectional view of the chain saw having a large arcuate saw guide incorporated therewith for cutting the exterior of the semi-tubular shape;

Fig. 7 is an enlarged detailed sectional view of the chain saw having a smaller arcuate saw guide incorporated therewith for cutting the interior of the semi-tubular shape;

Fig. 8 is an enlarged detailed sectional view of the chain saw having incorporated therewith two concentric guides;

Fig. 9 is a view in perspective of a typical insulative material block prior to the sawing operation;

Fig. 10 is a view of the partially completed semitubular structure formed by a single guide machine;

Fig. 11 is a perspective view of the completed semitubular structure:

Fig. 12 is a perspective view of one form of one of the interchangeable guides of the machine; and

Fig. 13 is a cross sectional detailed view of one form of the conveyor feed chain and pins.

While the invention is susceptible of various modifications or alternative constructions, there is shown in the drawings and described hereinafter in detail the preferred embodiments, and it is to be understood that the invention is not thereby intended to be limited to the specific forms disclosed, but that it is intended to cover all modifications and all alternative constructions falling within the scope of the invention as expressed in the appended claims.

Referring to Fig. l, numeral it} indicates one form oi the apparatus of the present invention.

. hers 17, 17. Supported in vertically adjustable relation upon vertical members 16, '16 by means of bolts or the like 18, 18, coacting with slots 19, 19 is a horizontal cross plate or similar member 20. This member has connected thereto a horizontally extending shelf 21 which supports drive motor 22. Drive motor 22 is the source of power for operatiodof the chain saw and feed conveyor described hereinafter. Extending forwardly from the shaft of this motor is a driving sprocket 23operably connected to'the shaft of the motor and supported in the adjustable horizontal plate 20. V

This driving sprocket 23 coasts in driving relation with a roller chain saw 24 which is composed of a plurality of pivotallyconnected links 25 each carrying forwardly directed teeth 26 and having spaces therein to engage the teeth of the sprocket. Carried on a transverse vertically extending plate 27, attached to vertical members 16, 16, are two transversely adjustable sprocket idlers 28, 28 which coact with chain saw 24. i These idler sprockets are horizontally adjustable in slot 29 formed-in the verticalplate 27 and may be clamped inadjustedposition by means of bolts or the like. These idler sprockets serve .to adjustably tension the chain saw in order to keep the saw taut and take up any slack caused by the substitution of different size guides, as described'hereinafte'r. Y

Removably mounted on the underside of table 11 is another horizontally extending transverse plate 30, Fig; 2,

having a transverse longitudinally extending slot 31 formed therein. Any particular selected chain saw arcuate shaped guide 32, best illustrated in Fig. 12, is mounted on this latter plate by means ofbolts or the like 33 projecting through vertically'extending slots 34, 3 4 formed in guide legs35, 35. The arcuateshaped-guide 32 has formed thereon an arcuate chainsaw supporting guide ledge 36 and may, if desired, have an additional upstanding guide flange (not shown) formed on the front of the ledge 36 in order to betterguide thechain saw on the guide. i j

"It.will be seenfrom the various figures ofthe drawings that the guide 32 has its legs35, projecting through horizontally. extending slots-37,' 37 formed through the work tablellj Work table il is removably attached to supportingmeans 14 bybolt s or the like, for a purpose described hereinafter. V v V Also formedin the surface of'work table His a slot 38,having any desired configuration, shown in the draw ings as circular. This slot has positioned therein a con-- veyor chain 39 preferably formed of a plurality of individual pivotally connected links40, '40. Each of these links 40, or any desired number thereof, carry upwardly extending pins or the like 41, 41. 'Pins 41 serve to hold 7 the work piece 42 which is impaled thereon, as described hereinafter. The conveyor chain 39 is driven by means of a suitable gearing mechanism 43, which may include a speed reduction transmission if so desired, which gearing system is driven by sprocket shaft 44, which coacts with a drive chain 45 driven by motor 22 through'sprocket 46.

As is best shown in Figures 6 and .7, the mechanism described herein is adaptable to a variety of. different The shaped and sized adjustable arcuate shaped guides. portion of these guides extending above the work'table may have any desired configuration, depending upon the particular semi-tubular shape Whichis to be fabricated. An alternative form of the device is shown in Fig. 8, wherein two concentric arcuate shaped guides 32 and 47 are utilized. It will be understood that the additional guide 47 has .coacting therewith an additional 'chain saw This apparatus comprises basically a work supporting table, indicated at 48, which saw is positively driven from motor 22 by an additional sprocket mounted on the drive shaft thereof. To tension the additional chain saw 48 additional idler sprockets similar to those shown at 28, 28 are positioned in horizontal slot 29 and adjusted to coacting relation with the additional chainsaw .to tighten the saw. The purpose of this alternative form of the structure will be described hereinafter.

In the embodiment of the invention illustrated in the accompanying drawings, it is desired that a semi-tubular elbow bend of insulative material, such as Styrofoam, cork, or the like, shown in Fig. ll, be formed from a starting block of this materials, indicated at 42 in Fig. 9.

The method by which the machine of the present invention accomplishes this fabrication is as follows: motor 7 22 is started and is adjusted to the desired speed by means of standard controls, not shown. Since this motor drives both the feeding conveyor chains 39 and the band saw 12, it willbe apparent that the work feed of the machine will always be synchronously related to the speed of the 'quire extremely fine positioning, then it may be desirable to: position the block on the conveyor feed chain '39 prior to starting motor 22; For thispurpose it may be desirable to incorporate in the gearing mechanism 13 a clutch member, not shown, to initiate operation of the feeding chain once the work piece is positioned thereon.

Convey or chain 39, carrying the block of insulative material 42, is rotated by the driving mechanism therefor in a counter-clockwise direction, as viewed in the drawings; to present the block tothe cutter teeth 26 of the portion of the chain saw 24- supported on arcuate shaped guide ledge 36 aboveth'e surface of the work table 11. 7

Continued rotation of the conveyor chain causes the block to move in a curved path past the saw station, resulting in the separation of'a curved solid semi-cylindrical portion 4 9 as illustrated in Figures 5 audit). The exterior surface of this portion forms the exterior surface of the final semi-tubular shape.

Where such a single arcuate'shaped guide form of the invention is utilized asshown in Fig. '6, the drive mechanism is stopped and a sccond guide 47 having 'a' smaller portion thereof .extendingabove the plane of the work table and being narrower across the'leg'portions thereof, but generally-similar in curvature to guide 32,

r is substituted for ;the guide'originally on the machine.

It'will be obvious'tha t where ap'lurality of similar semitubularshapes are to be fabricated, it is desirable to fabricate a" plurality of" the semi-completed blanks. 49 illustrated in FigsVS and '10 before changing the guides. The manner in which the guides maybe changed will be readily apparentfromthe above description'and frorn the drawings. 7 V 7 moved away from tensioning position, following which the" Idler sprockets 28 .are unclamped and chainsaw 24 is removed'from the arcuate shaped guide 32. The arcuate shaped guide 32 may then be readily removed from the horizontal mounting plate and the second guide'47 substituted therefor; The second guide 'is clamped infthe desired position; and the chain saw is positioned thereon. Following; this, the idler sprockets are moved :into erigagement'with the chain saw to'tighten; the saw and these sprockets :are .then clamped in their adjusted position.

the second arcuatle shaped guide in place the? op? erationof the.,de vice described above is repeated. Itlis to be emphasized that even ifthework pieces are removed.

from the conveyor after the first cut in order to manufacture a plurality of semi-completed blanks, they may be readily repositioned on the conveyor chain by reregistering the holes formed in the blank by pins 41 in the first operation. The drive mechanism is again started and the semi-completed blank is fed by the conveyor chain past the chain saw in the manner illustrated in Fig. 7, cutting an inside portion 5%) out of the semi-cornpleted blank. This results in the fabrication of the semitubular shape 51 shown in Fig. 11.

Where it is desirable to produce the semi-tub I in one operation rather than in two, the form of appa atus illustrated in Fig. 8 is utilized. in this embodiment of the invention, the two chain saws 24 and 48 are mounted respectively on concentric guides 47 and 32. In consequence, when the work piece is fed in a counterclockwise fashion past the saw station, completed semi-tubular shape 51 will be formed in opera ion. It is to be noted that the registerin holes are formed by pins M in the discarded portion 50 of the starting block, so that there is no marring of the finished product.

The height of the selected arcuate shaped guide above the surface of the work table, the width of this guide, and its configuration as to curvature will determine the cross sectional dimensions of the fabricated semi-tubular shape. By appropriate selection of the configuration of this arcuate shaped guide any desired cross sectional shape may be obtained. in like fashion, the thickness of the fabricated semi-tubular shape is determined by the dimensional differences between the larger and smaller guides. in some instances it is desirable that such insulation have non-uniform thickness, which may be readily accomplished by appropriate selection of the configuration of the guides. it will be obvious that it is possible with the method and apparatus of the present invention to fabricate a semi-tubular shape covering less than 180 or more than 180, if this is desirable.

It is within the scope of the present invention to supply a flexible guide so that this guide can be adjusted, at least over a limited range, without being completely removed from the machine.

The axial curvature of the semi-tubular shape will be determined by the dimension and curvature of the conveyor chain. The form of the device illustrated in the accompanying drawings has been shown for the formation of elbows with the axes of the saw guide curved portions perpendicular to the axis of the cooperating conveyor curved portion. The axial curvature of the semi-tubular shape may be changed by removing the work table from the remaining portion of the machine and substituting other work tables having difierently shaped slots 38 and conveyor chains 32?. Accord ly, various degrees of curvature may be fabricated in the semi-tubular shapes. As an al ernative to this substitutional method, the conveyor chain may be positioned by means of a plurality of adjustable sprockets formed in the surface of the work table, so that adjustment of the sprockets will adjust the curvature of that portion of the chain which traverses past the saw station. One suit able embodiment of mechanism for this alternative structure is a system of idler sprockets and substitutable guides for the conveyor chain, this adjustable conveyor system being substantially identical with that described above and illustrated in the drawings for use with the chain saw. Any similar structure known in the art may be utilized for this purpose.

While the machine and method of the present invention are best suited for use with light weight cellular material, such as styrofoam or cork, it will be apparent that other similar materials which are capable of being positioned upon pins 43 may be fabricated.

We claim:

1. An apparatus for producing axially curved semitubular shapes comprising a supporting member having a substantially plane work support surface, an endless saw having horizontally directed teeth, a veitically extending U-shaped saw guide structure having legs adjustably and removably supported on said support and having a substantially semicircular curved base portion connecting juxtaposed ends of said legs and extending above said support, said guide carrying said saw in supporting and gui ing relation on said substantially semicircular curved guide portion whereby to saw a substantially semi-circular section from a block of material, and a Workfeeding conveyor positioned on said support in the plane of said work support surface and having for conveying material on said work support surface, said conveyor extending through said curved saw supporting guide portion and having a work-carrying portion with a substantial curvature passing between said legs of said guide and around an axis of curvature extending direction perpendicular to the direction of the axis of curvature of said curved guide portion.

2. An apparatus for producing axially curved semitub ar shapes comprising a supporting member having a substantially plane work support surface, an endless flexible saw, a saw guide including leg portions mounted on said support and having a substantially semicircular curved portion extending thereabove, said guide carrysaid aw in supporting and guiding relation on said curved guide portion whereby to saw a substantially semi-circ r section through a block of material, an cndles wor ceding conveyor traveling in the plane of said work support surface and positioned on said supporter having means for carrying a block of onveyor portion extending in a directo the direction of the axis of curvaled guide portion whereby said block of i is carried into sawing engagement with said saw a curved path around the axis of the curved conveyor portion through the saw, and power means connected in driving relation to both said conveyor and said saw in a man er to drive both simultaneously in a predetermine speed relationship.

3. An apparatus for producing axially curved semitubular shapes comprising a supporting member having 1 lane work support surface, an endless saw having hor'zontally directed teeth, a saw guide sai' supporting member and having a substantially sen1ic"ular curved portion extending thereabove, said uide carrying said saw in supporting and guiding relation on said substantially semicircular curved gui portion above said s pport whereby to saw a substanti -iy semicircular section from a block of material, a Work-feeding conveyor traveling in the plane of said Work support surface and positioned on said support and having means for conveying material with a face thereof on said work support surface, said conveyor extending through said curved saw supporting guide portion and having a Work carrying portion With a substantial curvature around an axis of curvature extending in a direction perpendic .r to the direction of the axis of curvature of said curved guide portion whereby said block of material is carried into sawing engagement with said saw in a curved path around the axis of the curved conveyor portion, an adjustable tensioning means on said supporting member in coacting relation with said saw for tensioning said saw.

4. An apparatus for producing axially curved semitubulu. shapes comprising a supporting member having a substantia ly plane support surface, an endless saw, a saw guide mounted on said supporting member and havin' a substantially semicircular curved portion extending thereabove, said guide carrying said saw in supporting and guiding relation on said substantially semcircular curred guide portion above said support whereby to saw a substantially semicircular section from a block of material; and a work-feeding conveyor traveling in the plane of said support surface and positioned on said support and having upwardly extending pin means for conveying material with a face thereof on said support surface, said conveyor extending through said curved saw supporting guide portion and having a work carrying portion with asubstantial curvature around an axis of curvature extending in a direction perpendicular to the'direction of the axis of curvature of said curved guide portion whereby said block of material is carried into sawing engagement with said saw in a curved path around the axis of the curved conveyor portion.

' 5. An apparatus for producing axially curved semitubular shapes comprising a supporting member having a substantially plane support surface, a first endless flexible saw, a first saw guide including legs mounted on said supporting member and having a substantially semicircular curved portion extending thereabove, said first guide'lcarrying said first saw in supporting and guiding relation on said first guide curved portion, a second endless flexible saw, a second saw guide including legs mounted on said supporting member and having a substantially semicircular curved portion of a difierent diameter from said first guide curved portion arranged 8 within said first guide curved portion and extending above said support surface, said second guide carrying said second saw in supporting and guidingrelation on said second guide curved portion, work-feeding 'con-;

veyor positioned on said support and having means for carrying ;a block of working material, said conveyor having a portion thereof passing in a curved path between said legs of said guides whereby said block of matenial is carried into sawing engagement with said saws inta curved path and an axially curved semitubular shape is formed from the block of material References Cited in the file of this patent UNITED STATES PATENTS 17,871 Collins July 28, 1857,, 81,434 Thompson Aug. 25, 1868 111,414 Watson July 31, 1871 186,293 Balch Jan. 16, 1877 397,727 King, Feb. 12, 1889 1,054,693 Klingele Mar. 4, 1913 1,473,961 McPhee Nov. 13, 1923 2,751,941 Smith June 26, 1956 FOREIGN PATENTS Great Britian Feb. 10, 

